SBIR-STTR Award

The proposed program seeks to develop an electrified smart rotor head to enable unique VTOL aircraft configurations by significantly reducing the mechanical complexity of existing variable blade pitch rotor heads seen on traditional VTOL aircraft such as helicopters and tilt?rotors. The proposed end?use will integrate high reliability non?contact power and data couplings and in?hub electric servos to actuate the rotor blades of a VTOL lift rotor. The initial target market for this application will be lift rotors for UAS systems with MGTOW ranging from 800?1,300lbs (upper Group 3). In Phase I of the project, ESAero will partner with Cal Poly to conduct a comprehensive feasibility study and conceptual design effort. This effort will incorporate the build and verification of prototype rotor mechanisms to verify design spirals for early risk identification. ESAero and Cal Poly will jointly explore the design space utilizing collective design and analysis capabilities including aerodynamic CFD analysis, and static and dynamic structural FEA analysis. ESAero will lead and execute the manufacturing efforts for prototype mechanisms. Cal Poly will support the testing and verification of the mechanisms utilizing the wind tunnel and structures testing facilities as required. Phase I will culminate in a planning effort to mitigate any risks identified in the design effort. The end of Phase I will also identify an ideal transition end?user for Phase II. In Phase II, the team will work closely with the transition partner to transition the technology through full feature implementation including optimized individual blade control, full scale design verification, and an initial operational trial on a Group 3 UAS.

Helicopters have traditionally solved the need for vertical flight by transmitting and manipulating the power from a relatively constant speed gas turbine to different areas of the helicopters flight control system. The current revolution in electric vertical flight is changing this paradigm and the mechanical simplicity of batteries and electric motors are replacing the complex transmissions and linkages of traditional helicopter flight controls. The proposed solution is an Electrified Rotor Head (ERH) that simplifies the traditional helicopter rotor. The ERH concept integrates the advantages of Individual Blade Control (IBC) with modern electronics and actuators to provide optimized blade pitch control and achieving new levels of performance unattainable with traditional mechanical swashplates. This technology is based on advancing the full-scale testing and benefits realized by NASA and the U.S. Army Aero-Fight Dynamics Directorate (AFDD) during the Individual Blade Control Projects of the late 90’s and 2000’s which measured a 7% efficiency improvement, 85% vibration reduction, and reduction in 11dB rotor acoustics in the NASA AMES 40’x80’ wind tunnel. The ERH technology can add significant value to aircraft under development with Agility Prime, as well as group 3 and 4 VTOL UASs. In Phase I the ERH technology transitioned from idea to demonstrated physical system with a supporting sizing study showing potential application to aircraft from 55lbs to 10,000lbs. In Phase II Empirical Systems Aerospace proposes to resolve the remaining barriers to adoption and use of the ERH technology through a reliability study, a reliability focused design cycle, a flight demonstration, and finally a productization effort. Phase II will address reliability risks with a quantitative FMECA study and implementation of reliability enhancements. The system will then enter a design cycle with the outcome being a free-flight hover and forward flight demonstration on ESAero’s SMART UAS, a 110lb GTOW eVTOL for testing full scale vehicle handling qualities. The effort will complete with the documentation and delivery of a technical data package as well as two flight ready ERH units to TPOCs in the Air Force Operational Energy office for evaluation. During the Phase I, ESAero has been in discussion with multiple interested parties and has successfully obtained a customer MOU. The support of the Air Force gives significant weight to the benefits of increasing VTOL aircraft efficiency and reducing the necessary logistics to refuel and resupply.